import React, {Component} from 'react';
import Child from "./components/Child";

class App extends Component {
    state = {num:10}
    render() {
        return (
            <div>
                <button onClick={()=>{this.setState({num:200})}}>点击修改</button>
                {this.state.num}
                <Child/>
            </div>
        );
    }
}

export default App;